package test;public class testThread{    public static void main(String[] args)    {        Example example = new Example();        Example example2 = new Example();        Thread1 thread1 = new Thread1(example);        Thread1 thread2 = new Thread1(example2);        thread1.start();        thread2.start();        //        Example example = new Example();//        Thread2 thread1 = new Thread2(example);//        Thread2 thread2 = new Thread2(example);//        thread1.start();//        thread2.start();    }}class Example{    public void execute()    {        for (int i = 0; i < 10; ++i)        {            try            {                Thread.sleep((long) Math.random() * 1000);            }            catch (InterruptedException e)            {                e.printStackTrace();            }            System.out.println("Hello: " + i);        }    }    public synchronized void execute2()    {        for (int i = 0; i < 10; ++i)        {            try            {                Thread.sleep((long) Math.random() * 1000);            }            catch (InterruptedException e)            {                e.printStackTrace();            }            System.out.println("World: " + i);        }    }}class Thread1 extends Thread{    private Example example;    public Thread1(Example example)    {        this.example = example;    }    @Override    public void run()    {        example.execute();    }}class Thread2 extends Thread{    private Example example;    public Thread2(Example example)    {        this.example = example;    }    @Override    public void run()    {        example.execute2();    }}